Results of surveys of hazardous air pollutants

Last Updated April 7, 2021

The Institute for Environmental Science conducts surveys of hazardous air pollutants in the environment.
On this page, we will inform you of the survey results.
For an overview of the survey, see the survey page on air and water environment.

Hazardous air pollutants measured by the Institute for Environmental Science

The 15 harmful air pollutants measured by the Institute of Environmental Science are as follows.
Benzen, trichloroethylene, tetrachloroethylene, dichloromethane, acrylonitrile, acetaldehyde, vinyl chloride monomer, methyl chloride, chloroform, 1,2-dichloroethane, 1,3-butadiene, formaldehyde, benzol (a), pyrene, dioxin, dioxin, dioxin, dichloride, dichloroethylene, dichloroethylene, 1, 1, 1, dichloroethylene, 1, 1, 1, formalde, 1, formalde, 1, 1, 1, 1, chlorodehydehydehyde, 1, chloroethylene, 1, 1
For dioxins, please refer to the Environmental Environmental Pollution Monitoring Center page.

Survey results of benzene, trichloroethylene, tetrachloroethylene and dichloromethane

Survey results of acrylonitrile, acetaldehyde, vinyl chloride monomer, methyl chloride, chloroform, 1,2-dichloroethane, and 1,3-butadiene

Survey results of formaldehyde, benzo(a) pyrene and toluene

Survey points

There are five survey points in Yokohama City.
Shiota conducts surveys every year, and in Miho and Takigashira, surveys are conducted in even-numbered years, and in Honmoku and Yazawa, odd years.

Location map of survey points

(Reference) About regional classification

"General environment" is a point where it is considered not directly affected by the emission of harmful air pollutants from fixed sources or mobile sources.
"Around fixed sources" is a point where the concentration of substances that are expected to emit harmful air pollutants at fixed sources is considered to be relatively high compared to other locations on fixed sources.
"Roadside" is a point where the concentration of harmful air pollutants expected to be emitted from automobiles is considered to be relatively high compared to other places along the road.

Results of the survey

The survey results are shown for 14 of the 15 substances measured by our laboratory, excluding dioxins, according to the prescribed standards.

Results of surveys of four substances subject to environmental standards

Benzene, trichloroethylene, tetrachloroethylene, dichloromethane

Of the 14 substances measured by our laboratory, the survey results of four substances with environmental standards (benzene, trichloroethylene, tetrachloroethylene, dichloromethane) are shown.

Environmental standards are standards set based on the Basic Environmental Law and are desirable to be maintained to protect human health and preserve the living environment.

Environmental Standards
Substances	Environmental Conditions
Benzene	The annual average value is 0.003 mg / m3 (3 μg / m3) or less.
Trichloroethylene	The annual average value is 0.13 mg / m3 (130 μg / m3) or less.
Tetrachloroethylene	The annual average value is 0.2 mg / m3 (200 μg / m3) or less.
Dichloromethane	The annual average value is 0.15 mg / m3 (150 μg / m3) or less.

Graph of the measurement results of benzene Benzene (environmental standard: 3μg/m3)

Graph of measurement results of trichloroethylene Trichloroethylene (environmental standard: 130 μg/m3)

Graph of the measurement results of tetrachloroethylene Tetrachloroethylene (environmental standard: 200 μg/m3)

Graph of the measurement results of dichloromethane Dichloromethane (environmental standard: 150 μg/m3)

At the beginning of monitoring in 2000, there were some points that exceeded the environmental standard values, but all of them were on a downward trend, and since fiscal 2003, almost no longer exceeded the environmental standards.
For trichloroethylene, tetrachloroethylene, and dichloromethane, no point exceeding the environmental standard was observed since the beginning of monitoring.

Survey results of 7 substances with guideline values

Acrylonitrile, acetaldehyde, vinyl chloride monomer, methyl chloride, chloroform, 1,2-dichloroethane, 1,3-butadiene

Of the 14 substances measured by our institute, 7 substances with reference values (acrylonitrile, acetaldehyde, vinyl chloride monomer, methyl chloride, chloroform, 1,2-dichloroethane, 1,3-butadiene) are shown.

Guideline values are numerical values that serve as guidelines for reducing health risks caused by harmful air pollutants in the environment.

About guideline value
Substances	Environmental Conditions
Acrylonitrile	The annual average value is 2 μg/m3 or less.
Acetaldehyde	The annual average value is 120 μg/m3 or less.
Vinyl chloride monomer	The annual average value is 10 μg/m3 or less.
Methyl chloride	The annual average value is 94 μg/m3 or less.
Chloroform	The annual average value is 18 μg/m3 or less.
1,2-dichloroethane	The annual average value is 1.6 μg/m3 or less.
1,3-butadiene	The annual average value is 2.5 μg/m3 or less.

Graph of the measurement results of acrylonitrile Acrylonitrile (guided value: 2 μg/m3)

Graph of the measurement results of acetaldehyde Acetaldehyde (guided value: 120 μg/m3)

Graph of measurement results of vinyl chloride monomer Vinyl chloride monomer (guided value: 10 μg/m3)

Graph of measurement results of methyl chloride Methyl chloride (guided value: 94 μg/m3)

Graph of the measurement results of chloroform Chloroform (guided value: 18 μg/m3)

Graph of measurement results of 1,2-dichloroethane 1,2-dichloroethane (guided value: 1.6 μg/m3)

1,3-Graph of the measurement results of butadiene
1,3-butadiene (guide value: 2.5 μg/m3)

For acrylonitrile, acetaldehyde, vinyl chloride monomer, methyl chloride, chloroform, 1,2-dichloroethane, and 1,3-butadiene, no point exceeded the guideline values from the beginning of monitoring.